Development of complicated products is a project of system engineering It involves extensive and complicated knowledge,design methods and auxiliary technology Various factors affect each other So,modern product development is a typical group problem with distributed and dynamic features It is apparent superiority to solve this problem with a multi agent system representing various knowledge domains Distributed artificial intelligence knowledge being used,the multi agent collaborative design system concept and model based on Internet environment are put forward The realizing method of product developing agents,interactive process among multi agents,and organization and implementing of the design project of the multi agent collaborative design system are discussed in detail Application examples are also presented. Development of complicated products is a project of system engineering It involves extensive and complicated knowledge, design methods and auxiliary technologies Various factors affect each other So, modern product development is a typical group problem with distributed and dynamic features It is apparent superiority to solve this problem with a multi-agent system representing various knowledge domains Distributed artificial intelligence knowledge being used, the multi-agent collaborative design system system concept and model based on Internet environment are put forward The realization method of product developing agents, interactive process among multi agents, and organization and implementing of the design project of the multi-agent collaborative design system are discussed in detail Application examples are also presented.